Add shadow to expanded search box

Change-Id: I6fa3bdd20a4e1fe024e2edabc06d0f777571ae2c
diff --git a/src/com/android/dialer/DialtactsActivity.java b/src/com/android/dialer/DialtactsActivity.java
index c164294..8445ff7 100644
--- a/src/com/android/dialer/DialtactsActivity.java
+++ b/src/com/android/dialer/DialtactsActivity.java
@@ -323,6 +323,7 @@
         final ActionBar actionBar = getActionBar();
         actionBar.setCustomView(R.layout.search_edittext);
         actionBar.setDisplayShowCustomEnabled(true);
+        actionBar.setBackgroundDrawable(null);
 
         mSearchEditTextLayout = (SearchEditTextLayout) actionBar.getCustomView();
         mSearchEditTextLayout.setPreImeKeyListener(mSearchEditTextLayoutListener);